A．round and strongB．very dard C．made of only grassD．bui……

B The California region boasts a wide variety of climates and geographical features, rivaline any other area of comparable dimensions, Nearly all but the easten—edge California Native Americans lived where environmental conditions were favorable making food realatively accessible Califomia tribes as the Chumash, Yourok and Pomo.The MAaidu and Pomo principally ate acorns, which have a higher calorie rating than wheal, They pounded the hard nuts with stones and washed out the bitter taste with water. The Pomo crafted what were arguably the finest baskets in all indigenous America.They made baskets as small as a thimble and as bid as a yard in width. They made watertight baskets.For Cooking acom nush and seed grues as well as for carrying and storing food. They wore especially beautiful baskets for presents and as offerings to forebrain.Some were bedecked with colorful bird featers and shells , their skill also was applied to trays,boats,headgeat and baby carries such as a wickerwork cradleboard in which an infant spent his first Their mothers wore hats that resembled bowl—shap baskets. The Califomia natives lived in communities numbering up to 2000 with dwelling arrayed in groups Ahouse consisted of a round framc covered with grass.There was a sky light in the root and the beds were made a cook fire for seeds nuts fish and other foods More than 100 languages flourished in California before European contact most are gone today.From the passage We know that their houses（ ）

A．round and strong
B．very dard
C．made of only grass
D．built in groups